Fuel-injection delivery measurement

A computer program product for computing quantity of fuel injected into an engine, the computer program product comprising non-transitory computer readable storage medium that comprises computer executable instructions to:

• store rail pressure values received from the engine to a first buffer using a first direct memory address channel;
• copy a first subset of the rail pressure values from the first buffer to a filter module using a second direct memory address channel, in response to an angle-based interrupt request;
• copy filtered pressure values from the filter module to a second buffer using a third direct memory address channel;
• compute a pressure drop based on the filtered pressure values from the second buffer;
• and
• compute a quantity of fuel injected into the engine based on the pressure drop.

A computer-implemented method for measuring fuel injected into an engine, the computer-implemented method comprising:

• continuously storing rail pressure values from the engine into a first buffer using a first direct memory access channel;
• and
• in response to an event indicating that the engine is at a predetermined angular position:
• capturing a working memory address of the first direct memory access channel, wherein the working memory address is an address from the first buffer at which a last rail pressure value is last stored;
• filtering subsequent rail pressure values, starting at the working memory address, from the first buffer into a second buffer using a second direct memory access channel;
• computing a pressure drop from the rail pressure values that are stored in the second buffer;
• and
• computing a quantity of fuel injected into the engine based on the pressure drop.